Flotation of mica with sulfonates



Patented June 30, 1953 UNITED STATES PATENT ICE FLOTATION F MICA WITHi SULFONA'TES Elmer William Giesek-e, Fountain City, 'llenni,.as

signor to American Cyanamid flompany, New- York, N. Y., a corporation of Maine No Drawing.

ApplicationNovcmber 26, 1949;

The present: inventionrelates to. the concentration, of mica by. froth. flotation. More particularly, it concerns. an improved; anionic. reagent: combination for the frothfiotationof: mica.v "line: invention. contemplates both the reagentcombrrnation and the improved processofflotation usin the combination. I

- Therev exists a marked commercial demand; for micas: for various purposes. of themost common: mineral types in the earths surface, deposits sufficiently free from. quartz, for various commercial: purposes,' are not readily found. Accordingly, various attemptshave been, and. are being, madeto beneficiatemicaby froth flotation to. obtain. mica. concentrate of saleable grade. 1 a

lnithis-connection, theuse of the terms m1ca. or: mi'cas is intended generally to. cover: vari ous: minerals, particularly muscovite. lepidolite,

. mented ordinarily by use. in conjunction With sulfuric acid and an. aluminum. salt such. as alum or aluminum chloride.

Although in many cases; acceptable concentrates can be obtained; the practice'is notwholly. satisfactory for a number of: reasons. In. many cases-ythe ratio of concentration is notsufficiently high. Inmany cases, due to the expensive re.-

agent used, control mustbe maintained with. ex-

cessive care; Further, because of: the sensitivity of the cationic agents to slimes, ore pulp: must be carefully deslimed. Still further, the choice of:

the amount of selected reagent to be used, must be carefully made and maintained becausc of. the ability of the amineto float quartz, as Well as. the silicates. aluminum salts, were required for this purpose. Last, but not least, the overallioperation was more expensive than was generally considered desirable.

It is, therefore, the principal object of the present invention to provide a froth flotation process.

which is not subject to theselimitat'ions. The

reagents used should not be particularly expen- Supplemental aluminum salts should notv be essential. The degree of care required in their useishouldnot be excessive; The process should; not be; unduly sensitive to the. presence/of: slimes sive.

in the ore slurry being treated.

While mica; is. one

Supplemental agents, usually:

, 2 Surprisingly, in. View ofthenature of the mineral. being concentrated; these objects have been accomplished by a flotation; using an anionic reagent in an; acid; circuit; In addition to the acidic material, the reagents used; comprise sulfonated petroleum hydrocarbona. preferably supplementedI by a commercial diaryl dithiophosphate. The successful accomplishment of. the desired objects in an anionic circuit, with these reagents, is particularly surprising, in view. of the past use, considered necessary in.the.ar.t,.ofs com.- merical cationic-type; reagents in: cationic flotation.

Safari as conditions of acidity arev concerned, the; requirements are: not too; restrictive; It has I been: found that successful; results can. be produced. under conditions; at which the-- pi k-value. isabout 6.0.: or less There is: no particular ad:- vantage in going below a pH of about 2.51, al:- though there is; noparticular. harm. in so doing. Substantially: any acid-forming substance, capable'of producing the; desired pH: conditions, may

be used; Commercially, however, this is substantially; limited to the use, of: inorganic mineral acids, particularly sulfuric acid; The latter, because of; --its general availability; is to: be preferred. Hydrofiuoric acid, on, the other hand, should; be avoidedrs-ince; this acid exerts a depressing; efiect: on: mica: when using the prometers of.- the present; invention- Sulfonated petroleum: hydrocarbons, such as.

, example, ill-U. S. Patent 2;331p049, their principal source. is. as by-products from the refining of petroleum lubricating oil fractions in the course of: treatmentwith fuming sulfuric. acids or sulfuric-acids: When soproduced; these by-products are: generally foundtobe salts of the sulfonated hydrocarbonszli Most commonly, the metallic radical-of the saltis sodium. However, salts of othermetals, such asv the alkaline earth metals, aluminum, and" the like, are encountered. In some cases, no attempt hasbeen made to neutralize the acid product. Even after neutralization, free sulfonates and/or sulfates are often found.

So far as the present invention isconcerned,

. it makes: little difierence whether the. sulfonated petroleumhydrocarbonis used per se or as a salt;

whether or; not: the sulfur is; present, in a sulfate or-asulfonic group, there. usually being some of both present; or whetherthe-compounds are used ,as. salts of sodium, potassium, calcium, barium, aluminum, and the like. Nor need the materials be purified, since mixtures of compounds produce wholly satisfactory results. As used in the present case, the term sulfonated petroleum hydrocarbons is, therefore, intended to include such mixtures as are found in the commercial products. 1 a

Petroleum sulfonates, or derivatives thereof, which are suitable for use according to the process of the present invention are commercially" available under a variety of designations. Among these found to be useful are Petronate and O-Emulsifier, obtainable from L. Sonneborn Sons; Eldrol and Petro'sul, obtainable from Pennsylvania Oil Products Refining Co.; Sherwood Reagent 407, obtainable from Sherwood Refining Co.; Ultranate No. 2, obtainable from Atlantic Refining (20.; and SP-l, SP- 302, and SP-312, obtainable from Stanco Distributors, Inc.

However, the commercialy-available, sulfonated petroleum hydrocarbons may be divided on a functional basis into two distinct groups. One of these is the group variously known as mahogany" acids, mahogany soaps, and the like. This group is characterized in that its constituents are generally oil-soluble but water-dispersible. Usually, but not necessarily, these compounds have a deep mahogany color when in solution, which gives rise to the generic designation as mahogany" compounds.

The other group is generally, but not necessarily, characterized by a green coloration in solution. Hence, compounds of this group are usually referred to as green sulfonic acids or green, soaps. More important than the color distinction, however, is the fact that the so-called green compounds are characterized by being watersoluble.

So far as the present invention is concerned, either group, or a mixture thereof, may be used.

'In using the green type of petroleum sulfonates,

which are generally, but not necessarily, preferred in the process of the present invention, it will be found that, while they are generally characterized as water solubla-this is usually of sufficiently high degree that the use of the reagent alone may not always produce the optimum concentration. These green compounds appear to lack certain water-repellentproperties which are helpful in making successfulconcentration. In the process of the present-invention, this difficulty is readily overcome by the addition of an amount of a more hydrophobic material. This may be done by adding an oil in suitable quantity or by mixing some of the oil-soluble petroleum sulfonates with the water-solubletype. Any of the commercially-available oils of animal, vegetable, or mineral origin may be used for this purpose. Unsulfonated petroleum derivatives, such as crude oil, kerosene, or fuel oil, are very suitable. Saponifiable oils, such as coconut oil, cotton seed oil, and other, glyceride oils may be used. 'Anionic' materials, such as the fatty'acids and the like also may be used, provided the gangue constituents are such as not to be floated by these materials. Tall oil, in view of its low cost, is especialto constitute a good average practice. In using 4 the supplemental oiling agent, it will generally be found that from about 0.5-5.0 pounds per ton is also a good operating range. Usually, about 1-2 pounds per ton will constitute a good average practice.

7 As was pointed out above; oneof of principal objects of the present invention is that the process not be unduly sensitive to the presence of slimes. As compared with the use of cationic reagents, in a cationic circuit, this will be found true of the process of the present invention. However, in order to produce a cleaner product and, in many case, reduce the reagent consumption, a simple desliming is generally found desirable. Thismay be carried out in any desired manner, in accordance with conventional practice. Usually, this is done by hydraulic classification. With many samples, it will be found that this has also an additional advantage, in that the smaller particle size fractions, i. e., those below about 200 to 150 mesh, frequently contain a higher proportion of the objectionable quartz than do the larger size fractions, i. e., those from the range of about plus 48 to plus 150 mesh; Therefore, a

late material is pulped in water and deslimed, if

such an operation is to be used- The use of caustic in the desliming operation is found to be helpful, but not essential. The deslimed sands are then usually conditioned with the flotation reagents. necessarily, carried out at approximately pulp flotation density. Generally this constitutes some 18-25% solids. A rougher flotation is then carried out, and this is generally followed by a cleaner float and, generally, a second cleaner float. In the cleaner notations, it is usually desirable to add a small amount of additional frother, in order to produce the best results. In addition, if, through dilution, there is not suificient acid to maintain the desired pH, a small amount of make-up acid may be used.

It is believed that the invention will be more readily understood in conjunction with the following examples. These are given as illustrative only, and not by way of limitation. Except as otherwisenoted, all parts are considered-t0 be parts by weight. In reporting the following examples, the reagents have been given alphabetical designations, in order to simplify the tables. In the tables, the following reagent designations are used:

A, sodium hydroxide B, sulfuric acid C, technical grade alum D,'com mercial alcoholic froth'er averaging from 7-8 carbon atoms E, commercial aliphatic amines mixture averag-' ing 18 carbon atoms 7 F,.commercial water-soluble green petroleum sulfonate G, 22 Baum fuel oil I H, a commercial cliaryl dithiophosphate ing 5-10% thiocarbanilid I, commercial steam-distilled pine oil.

contain- The conditioning is usually, but notamamzc improvement is one of thecritical factors. Commercially, it is of equal importance with the mica recovery.

EXAMPLE 1 in the art, using cationic-type flotation. A'clean mica concentrate, amounting to 26.2% by weight of the original sample, and having a density-of 49.6 pounds per cubic foot, was obtained. This concentrate contained about 74% mica and 26% This is a good representa- 61 mesh, containing 97% mica and 3% quartz; 50.1% by weight was minus 150 mesh and contained 93% mica and 7% quartz. If a greater recovery is required, it ;can be done by taking advantage of the third cleaner float, which was added in this example. Combining the clean micaconcentrate :with the third cleaner tail, a

concentrate amounting to- 30.4% by weight of the feed, assaying about 94% micaand 6% quartz, is obtained, with a satisfactory density.

EXAMPLE 3 A sample of lep-idolite ore wassubjected to flotation, using the conditions and reagents shown quartz. Of the cleaner ccncentrate,'22.-1-% of the in the following Table III.

Table II I Material Mm Time, Percent Solids Grind (No Desliming.) Condition Sand Flotation ,First Cleaner Flotation.

' Sec. Cleaner Flotation wan s o'ooo weight was plus 100 mesh and averaged 99% mica and 1% quartz. About 78% of -th e concentrate was'minus 100 mesh and averaged a mica content of 70% with quartz.

Again, this is a good example-of the commercial prior art practice, using an amine in a cationic flotation. :A -clean mica concentrate is obtained, amounting to 39.5% by weight of the Table :I

T t Reagents ime ercen Matenal 7 Solids, pH.

A .B O D E Grind Deslime.

Condition Sand Flotation First Cleaner Flotation Sec. Cleaner F1otation 1 Reagents added after 1%.

. EXANH LE .2

In order to illustrate the "efiectiveness of the process of the present invention, another sample of the same ore was subjected to'fiotation, under the conditions, and using the reagents, shown in the following Table II.

feed, having a density of 38.1 pounds per cubic foot, containing 83% mica and'1 7-% quartz. The

Of the concentrate, 44.8% was plus 150' mesh, containing ratio of concentration is 2.53110.

98% micaand 2% quartz; the remainder, 55.2% by weight of -minus 150 mesh material, contained mica and 30% quartz;

Sec. Cleaner Flotation Third Cleaner Flotation A cleaned mica concentrate, amounting" to 26.9% by weight of the feed, and assaying mica and 5% quartz, was obtained. The ratio of concentration was 3.72:1.0. The concentrate EXAMPLE 4 Another sample of the same ore was subjected to flotation, under the conditions and using the contained 49.9% by weight of material plus 75 reagents shown in the following Table IV.

Table IV Reagents Material 'g fi f, lg r cigit pH V A F G H "In this operation, a concentrate amounting to 28.8% by weight, with a ratio of concentration of 3.47s1.0, was obtained. The density was 37.7 pounds per cubic foot, and it contained 98% mica and 2% quartz. Of the concentrate, 51% by weight was plus 150 mesh and49 was minus 150 mesh. Both fractions contained 98% mica and 2% quartz. This is a notable change from the result in Example 3, in which substantially the same proportions of plus 150 and minus 150 mesh material was obtained, but the minus 150 mesh fraction was very poor. grade and of high density.

All the mica ores of the above examples were substantially free of garnet.

I claim:

1. An improved process of; beneficiating mica ore which is substantially freeof garnet, which comprises forming an aqueous pulp of the sizereduced ore, conditioning the orepulp with ,a reagent combination comprising a strong inorganic mineral acid other than hydrofluoric, an oiling agent, a frother, and an anionic collector selected from the group consisting of water-soluble sulfonated petroleum hydrocarbons of the green acid type, water-insoluble petroleum sulfonates of the mahogany acid type, and miX- tures thereof, obtained in the refining of lubricating oil stocks, and the water-soluble salts of such sulfonates; subjecting the conditioned ore to aeration and agitation at a pH of less than 6 and collecting the purified mica as a froth concentrate, substantially free of gangue.

2. An improved process of beneficiating mica ore which is substantially'free of garnet, which comprises desliming the size-reduced ore, form-'- ing an aqueous pulp of the deslimed ore, conditioning the pulp with a reagent combination comprising a, strong inorganic mineral acid other than hydrofluoric, an oiling agent, a frother and an anionic collector selected from the group consisting of water-soluble sulfonated petroleum hydrocarbons of the green acid type, waterinsoluble petroleum sulfonates of the mahogany acid type and mixtures thereof obtained in the refining of lubricating oil stocks, and the watersoluble salts of such sulfonates; subjecting the conditioned ore to aeration and agitation at a pH of less than 6 and collecting the purified mica as a froth concentrate, substantially free of gangue.

3. An improved proces of beneficiating mica or which is substantially free of garnet, which comprises forming an aqueous pulp of the sizereduced ore, conditioning the ore pulp with a reagent combination comprising sulfuric acid, an oiling agent, a frother, and an anionic collector selected from the group consisting of watersoluble sulfonated petroleum hydrocarbons of the green acid type, water-insoluble petroleum sulfonates of the mahogany acid type and mixtures thereof obtained in the refining of lubricating oil stocks, and the water-soluble salts of such sulfonates; subjecting the conditioned ore to aeration and agitation at a pH of less than 6 and collecting the purified mica as a froth concentrate, substantially free of gangue.

4. An improved process of beneficiating mica ore which is substantially free of garnet, which comprises forming an aqueous pulp of the sizereduced ore, conditioning the ore pulp with a reagent combination comprising sulfuric acid, fuel oil, a frother, and an anionic collector selected from the group consisting of water-soluble sulfonated petroleum hydrocarbons of the green acid type, water-insoluble petroleum sulfonates of the mahogany acid type and mixtures thereof obtained in the refining of lubricating oil stocks, and the water-soluble salts of such sulfonates; subjecting the conditioned ore to aeration and agitation at a pH of less than 6 and collecting the purified mica as a froth concentrate substantially free of gangue.

5. An improved process of beneficiating mica ore which is substantially free of garnet, which comprises forming an aqueous pulp of the ore which has been reduced in size sufiiciently to pass through a 35-mesh screen, conditioning the ore pulp with a reagent combination comprising sulfuric acid, fuel oil, a frother, and an anionic collector selected from the group consisting of water-soluble sulfonated petroleum hydrocarbons of the green acid type, water-insoluble petroleum sulfonates of the mahogany acid type and mixtures thereof obtained in the refining of lubrieating oil stocks, and the water-soluble salts of such sulfonates; subjecting the conditioned ore to aeration and agitation at a pH of less than 6 and collecting the purified mica as a froth concentrate, substantially free of gangue.

ELMER WILLIAM GIESEKE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,043,192 Christmann June 2, 1936 2,257,808 Phelps Oct. '7, 1941 2,303,962 Tartaron et al Dec. 1, 1942 2,410,377 Booth et a1 Oct. 29, 1946 2,410,770 Booth et al Nov. 5, 1946 2,428,763 Booth et a1 Oct. 7, 1947 2,433,258 Booth et al. Dec. 23, 1947 OTHER REFERENCES Mining Technology, November 1944, T. P. 1754, pages 537-538. 

1. AN IMPROVED PROCESS OF BENEFICIATING MICA ORE WHICH IS SUBSTANTIALLY FREE OF GARNET, WHICH COMPRISES FORMING AN AQUEOUS PULP OF THE SIZEREDUCED ORE, CONDITIONING THE ORE PULP WITH A REAGENT COMBINATION COMPRISING A STRONG INORGANIC MINERAL ACID OTHER THAN HYDROFLUORIC, AN OILING AGENT, A FROTHER, AND AN ANIONIC COLLECTOR SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE SULFONATED PETROLEUM HYDROCARBONS OF THE GREEN ACID TYPE, WATER-INSOLUBLE PETROLEUM SULFONATES OF THE MAHOGANY ACID TYPE, AND MIXTURES THEREOF, OBTAINED IN THE REFINING OF LUBRICATING OIL STOCKS, AND THE WATER-SOLUBLE SALTS OF SUCH SULFONATES; SUBJECTING THE CONDITIONED ORE TO AERATION AND AGITATION AT A PH OF LESS THAN 6 AND COLLECTING THE PURIFIED MICA AS A FROTH CONCENTRATE, SUBSTANTIALLY FREE OF GANGUE. 